ch20

Strategies of Life

Chapter 20

Great Idea:Living things use many different strategies to deal with the problems of acquiring and using matter and energy

Chapter Outline

• The Organization of Living Things• What is Life?• Classifying Living Things• Survival: A New Look at the Life

Around You• Strategies of Fungi• Strategies of Plants• Strategies of Animals

The Organization of Living Things

Ways of Thinking about Living Things

• Levels – Biosphere – Ecosystem – Community– Population– Organism– Anatomy and physiology– Cellular– Molecular

• All levels complement each other

Study an Ant

What Is Life?

The Characteristics of Life

• High degree of order and complexity• Part of larger systems of matter and energy• Life depends on chemical reactions in cells• Life requires liquid water• Organisms grow and develop• Regulate energy use• Share same genetic code, code is heritable• All living things are descended from a

common ancestor

Organisms Need Energy

Organisms Grow and Develop

Science in the Making

• Measuring plant growth

• Jan Baptiste Van Helmont

• Plant tissue and CO2

Classifying Living Things

Cataloging Life

• Linnaean classification– Shared characteristics

• Hierarchy– Kingdom– Phylum– Class– Order– Family– Genus– Species

• Binomial nomenclature

Classification of Life

Classifying Life - cont.

• Kingdoms– Monera– Protista– Fungi– Plants– Animals

Five-Kingdom Classification

Monera

Protista

Different Division of Life

• Carl Woese– Molecular genetics– Three domains

• Bacteria• Archaea• Eucaryea

Science by the Numbers

• How many species are there?

Species Estimation

Classifying Human Beings

• Kingdom: Animals• Phylum: Chordates

– Subphylum: vertebrates

• Class: Mammals• Order: Primates• Family: Hominid• Genus: Homo• Species: sapiens

Primates

Implications of Linnaean Classification

• Use of DNA• Similarity depends on time and

change• Classification results from real events

Survival: A New Look at the Life Around You

Survival: A New Look at the Life around You

• Autotrophs• Heterotrophs• Dealing with complexity• Two basic tasks

– Obtain and distribute molecules for energy

– Reproduce

Strategies of Fungi

Strategies of Fungi

• Growth– Filaments– Decomposers

• Structure– Mass of filaments

• Reproduction– Break filaments– Asexual reproduction

• Spores

Fungi

Fungi – cont.

• Lichens– Two interdependent species

Science in the Making

• The discovery of penicillin– 1928– Alexander Fleming

Strategies of Plants

The Simplest Plants

• Phylum: Bryophytes• Structure

– No roots– Photosynthetic

• Reproduction– Sexual – Asexual

Bryophytes

Vascular Plants

• Phylum: vascular plants• Structure

– Roots, stems, leaves– Control water loss

• Reproduction– Seedless– Gymnosperms– Angiosperms

• Sexual and asexual

Design of Vascular Plants

Angiosperm

Strategies of Animals

Major Animal Phyla

Invertebrates

• Invertebrates– No backbone– Most diverse animals

• Arthropods– 70% of known animal species

• Structure– Exoskeleton

Arthropods

Three Main Body Segments in Insects

Vertebrates

• Organization– Ocean to terrestrial

• Evolution– Earliest fish– Bony Fish– Amphibians– Reptiles– Birds– Mammals

Modern Fish

Mammalian Family Tree

Thinking More aboutLife’s Strategies

• Eating through the phyla